Fundamental study on cooling of biological phantom using ice slurry in limited space

Abstract

The cooling process of a biological phantom using ice slurries with different geometries in a limited space was experimentally investigated. Ice slurry has recently been considered to as a solution to cool organs in the abdominal cavity efficiently and rapidly to suppress biological reactions during minimally invasive laparoscopic surgeries. However, previous studies have not focused on the interactions between ice slurry and biological tissues in the abdominal area. In this study, we aimed to investigate the effects of ice slurry geometry, enclosure width L_w, and mimic-blood flow rate Q_b on the cooling of a biological phantom using ice slurry in a limited space. We prepared the same volume of ice slurry using different geometries with an ice packing factor of 25 wt% using a scraper-type method to place on the phantom surface. We observed the melting behaviors of the ice slurries and measured the surface and core temperatures of the biological phantom. It was found that the supply methods of the ice slurry affected the cooling of biological tissues significantly. When the ice slurry width was the same as that of the enclosure, the ice slurry floated on the melted slurry and inhibited the cooling of the biological phantom. When the slurry width was small compared to that of the enclosure, the slurry remained in contact with the phantom, thus resulting in its efficient and rapid cooling. The mimic-blood flow promoted the melting of the ice slurry increased the heat flux on the phantom surface. However, the core temperature was not affected. Thus, the core temperature cannot be reduced unless the blood flow is occluded.